ナカムラ　カエ   NAKAMURA KAE   中村　加枝    所属   関西医科大学  生理学講座    職種   教授
言語種別	日本語
発表タイトル	Reward coding by the primate dorsal raphe neurons is context dependent.
会議名	第32回　日本神経科学学会
学会区分	全国規模の学会
発表形式	ポスター掲示
講演区分	一般
発表者・共同発表者	◎Nakao K, Matsuzaki R, Okada O, Kobayashi Y, Nakamura K
発表年月日	2009/09
開催地 （都市, 国名）	名古屋
概要	We have previously shown that the activity of neurons in the dorsal raphé nucleus (DRN), a major source of serotonin, is modulated by the received reward size. To study whether the DRN activity is involved in delay-based cost-benefit decision-making, we recorded single-neuronal activity in the DRN while a monkey performed a delayed-reward visually-guided saccade task. In the task, reward value (0.01 vs. 0.5ml) was indicated by the location of saccade target (right vs. left), and after saccade, a reward was delivered with a 1600ms delay. We found that about half (23/45) of DRN neurons exhibited sustained activity during the delay period 'after' saccade and before reward delivery, with either large- or small-reward preference. The same neurons often showed significantly less reward modulation if the delay (1600ms) was introduced 'before' saccade in a memory-guided saccade task. These results suggest that the coding of the size of delayed reward is dependent on the task context such as the sequence in a task.